Think You Could Do More if You Just Had an Extra Hand? You’re Probably Right.

BEYOND HUMAN. Prosthetic limbs have come a long way in recent years. From primitive designs that were little more than useless placeholders for the real thing, we now have high-tech devices that wearers can control with their thoughts. These prostheses can help people with missing limbs feel “whole” again. But in a new study, researchers set out to see if such devices could make humans more than whole.

Specifically, a pair of researchers from the Advanced Telecommunications Research Institute in Japan wanted to know if giving someone a supernumerary robotic limb (SRL), a mind-controlled robotic limb that worked alongside the person’s two biological ones, could give that person multitasking abilities beyond those of the average human.

They published their research in the journal Science Robotics on July 25.

TWO TASKS, THREE HANDS. For their study, the researchers asked 15 volunteers to sit in a chair with an SRL positioned as if it were a third arm coming from their own body. On the head of each volunteer, the researchers placed special cap that tracked the brain’s electrical activity. The cap transmitted that data to a computer that then translated it into movement in the SRL.

The result: all a volunteer had to do to control the SRL was think about an action.

Next, they asked the volunteers to complete two tasks. To accomplish one — balancing a ball on a board — they used their natural limbs. For the other (grasping and releasing a bottle), they used the SRL system. The researchers asked the volunteers to complete the tasks sometimes separately, sometimes simultaneously.

In 20 trials, the volunteers successfully completed both tasks using the three limbs about 75 percent of the time. In other words, they were able to complete two tasks simultaneously that would have been essentially impossible with just two limbs.

TRAINING THE BRAIN. When you think you’re “multitasking,” you aren’t actually paying attention to two things at once — your brain just switches rapidly between the two tasks. Past SRL systems required the user to concentrate on just the task at fake hand — this system is the first that could “read” a multitasking mind, sifting out the user’s intentions for the SRL. It can do this simply because it’s more advanced than previous versions.

The researchers even believe their system could essentially help humans become better at multitasking even when they don’t have a third limb helping out. “By operating this brain-machine interface, we have an idea that we may be able to train the brain itself,” researcher Shuichi Nishio told The Verge.

Future research will endeavor to figure out whether that’s true or not. If it is, we might be able to enhance our minds by temporarily enhancing our bodies.